Protestors, including relatives and sympathizers, shouted "We want truth" as Ma, protected by security guards, made his way to the funeral site at the soldier's home in the central city of Taichung.

The service was held a day after more than 100,000 people took to the streets of the capital Taipei to protest over the death of Corporal Hung Chung-chiu and the "sloppy" military investigation of the case.

Hung died of heatstroke on July 4 -- apparently after being forced to exercise excessively as punishment for taking a smartphone onto his base -- just three days before the end of his compulsory year-long military service.

Ma pledged no such tragedy would recur in the military as he offered his condolences to the family.

"As the president and the leader of the country's three armed forces, I hereby guarantee that Hung Chung-chiu will not have died in vain and such a tragedy will not happen again," Ma told Hung's father Hung Chi-tuan.

A total of 18 military officials were indicted last week over Hung's death, including the former commander of his brigade, after military prosecutors completed their investigation.